a) Field of the Invention
The present invention relates to novel thiazolidinedione derivatives and salts thereof. More specifically, this invention relates to thiazolidinedione derivatives or salts thereof which have excellent blood sugar-lowering activity and blood lipid-lowering activity, pharmaceutical compositions containing one or more of the compounds and methods for the treatment of diabetes.
b) Description of the Related Art
As synthetic hypoglycemic agents useful as therapeutic agents for diabetes, sulfonylurea preparations are widely used now. These sulfonylurea preparations, however, require very careful control during their use because they involve drawbacks such that they may cause critical and prolonged hypoglycemic symptoms or induce drug resistance.
There is accordingly the desire for development of a hypoglycemic agent serving as a substitute for such sulfonylurea preparations. Pharmaceuticals which can enhance the insulin sensitivity at peripheries and can show blood-sugar lowering action are increasingly attracting interests these days. However, these pharmaceuticals suffer from the disadvantage in that they produce undesirable side effects, and they do not posses sufficient blood sugar-lowering activity.
In addition, many cases of severe diabetics are accompanied by complications associated with hyperlipidemia. The development of a hypoglycemic agent which also displays blood-lipid lowering activity would be a useful pharmaceutical in the treatment of diabetes.